Molecular Characteristics of Hb New York [β113(G15)Val→Glu, HBB: c.341T>A] in Thailand

Abstract

Hb New York or Hb Kaohsiung [β113(G15)Val→Glu (GTG>GAG), HBB: c.341T>A] has been considered a rare β hemoglobin (Hb) variant found originally in an Iranian woman and later in diverse populations but its genetic origin has not been elucidated. Here we report molecular and hematological descriptions of this variant found in the Thai population. Among 5643 subjects referred for hemoglobinopathy investigation during January 2015 to September 2017, 183 (3.2%) were found to carry several Hb variants, including β chain variants (n = 135, 2.4%), α chain variants (n = 33, 0.6%), Hb Lepore-Hollandia (NG_000007.3: g.63290_70702del) and Hb Lepore-Boston-Washington (NG_000007.3: g.63632_71046del) (δβ hybrid Hb) (n = 12, 0.2%) and δ chain variants (n = 3, 0.05%). Of patients with β chain variants, six with normal high performance liquid chromatography (HPLC) patterns, had an abnormal Hb in zone 11 of capillary electrophoresis (CE), the amounts of which ranged from 29.6-45.4% with normal levels of Hb A₂ and Hb F. DNA analysis identified a heterozygous Hb New York mutation in all cases. Further screening of α-thalassemia (α-thal) identified coinheritance of α⁺- and α⁰-thal in two of them who had reduced levels of Hb New York. Haplotype analysis suggested that the Thai Hb New York was likely associated with a single β-globin haplotype [+ – – – – + +], indicating that it was of the same origin. Hematological findings and simple DNA assay based on allele-specific polymerase chain reaction (PCR) for rapid detection of Hb New York are presented.

Keywords:

• Hb Kaohsiung
• Hb New York
• northeast Thailand
• thalassemia

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This study was supported by the Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand. AC was supported by the New Researcher Development Program (2015), Khon Kaen University, Khon Kaen, Thailand. KS [contract number 59256] and HS [contract number 58438] are supported by the post-doctoral training program of the Graduate School of Khon Kaen University, Khon Kaen, Thailand.